Surveying Final
backsight
a sight taken with a level to a point of known elevation, thus permitting the surveyor to compute the elevation of the HI, in transit work the backsight is a sighting taken to a point of known position to establish a reference direction
barrow pit
a source of fill material that is located off the right of way
geographic information system (GIS)
a spatially and relationally referenced data base
catch basin
a structure designed to collect surface water and transfer it to a storm sewer
culvert
a structure designed to provide an opening under a road etc, usually for the transportation of storm water
geoid surface
a surface that is approximately represented by mean sea level (MSL), and is in fact the equipotential surface of the earths gravity field
automatic level
a surveyors level whose line of sight is automatically maintained in the horizontal plane, once the instrument is roughly leveled
grade transfer
a technique of transferring cut/fill measurements to the facility, i.e carpenters level, stringline level, laser, and batter boards
double centering
a technique of turning angles or producing straight lines involving a minimum of two sightings with a theodolite: once with the telescope direct and once with the telescope inverted
interlining
a trial and error technique of establishing a theodolite on a line between two points that themselves are not intervisible
gon
a unit of angular measure in which 1 revolution= 400 gon and 100 gon= a right angle, also known as grad
nadir angle
a vertical angle measured fromt he nadir direction (striaght down) upward to a point
grade stake
a wood stake with a cut/fill reference mark to that portion of a proposed facility adjacent to the stake
page check
arithmetic check
normal tension
the amount of tension required in taping to offset the effects of sag
deflection angle
the angle between the prolongation of the back line measured right (R) or left (L) to the forward line
azimuth
the angle to a line of sight, measured clockwise (usually) from a north meridian
latitude (of a course)
the change in northerly displacement of a line (Y)
drainage
the collection and transportation of ground and storm water
accuracy
the conformity of a measurement to the "true" value
clearing
the cutting and removal of trees from a construction site
geoid undulation
the difference between the geoid surface and the ellipsoid surface, N is negative if the geoid surface is below the ellipsoid surface
geodetic height
the distance from the ellipsoid surface to the ground surface
external distance
the distance from the mid-curve to the PI
mid-ordinate distance
the distance fromt he mid-chord to the mid-curve
coordinates
the distances measured north and east of a reference point having zero coordinates
accuracy ratio
the error in a measurement divided by the overall value of the masurement- expressed as a fraction with a numerator of 1 and a denominator rounded to the clsoest 100 units, example: an error of .01 ft in 30.00 ft would result in an accuracy ratio of 1/3000
elevation factor
the facor used to convert ground distances to sea-level distances
forced centering
the interchanging of theodolites, prisms, and targets into tribrachs- which are left in position over the station
polar coordinates
the location of a feature by angle and distance
alignment
the location of the center line of a survey or a facility
original ground
the position of the ground surface prior to construction
grubbing
the removal of stumps, roots etc from a construction site
gradient
the slope of a grade line
elevation
the vertical distance above or below a given datum; also known as orthometic height
hectare
10,000 square meters
arithmetic check
a check on the reductions of differential leveling involving the sums of the backsights and the foresights
skew number
a clockwise angle turned from the back tangent to the center line of a culvert or bridge
grade sheet
a construction report giving line and grade, i.e offsets, and cuts/fills at each station
traverse
a continuous series of measured (angle and distances) lines
free station
a conveniently locaated instrument station used for construction layout, the position of which is determined after occupation through resection techniques
circular curve
a curve with a constant radius
ground distance
a distance measured on the ground surface
grid distance
a distance on a coordinate grid
three-wire leveling
a more precise technique of differential leveling in which rod readings are taken at the stadia hairs in addition to the main cross hair
vertical curve
a parabolic curve joining two grade lines
station
a point on a baseline that is a specified distance fromt he point of commencement. the oint of commencement is identified as 0+00; 100 feet or 100 meters are known as full stations; 1+45.20 identifies a point distance 145.2 ft from the point of commencement
pre-engineering survey
a preliminary survey that forms the basis for engineerign design
intermediate sight
a sight taken with a level or transit to determine its elevation and or location
tangent
a straight line, often referred to with respect to a curve
property survey
a survey to retrace or establish propery lines or to establish the location of buildings within property limits
avulsion
a tearing away
spiral curve
a transition curve of constantly changing radius placed between a high-speed tangent and a central curve; it permits a gradual speed adjustment
zenith angle
a vertical angle measured downward fromt he zenith (upward plumbline) direction
orthometic height
also known as elevation, the distance from the geoid surface to the ground surface
vertical angle
an agnle in the vertical plane measure up (+) or down (-) from horizontal
datum
an assumed for fixed horizontal reference plane
data collector
an electronic field book designed to store field data- both measured and descriptive
total station
an electronic theodolite combined with an EDM and an electronic data collector
parallax
an error in sighting that occurs when the objective and or the cross hairs of a telescope are improperly focused
accretion
an increase by natural growth or by gradual external addition; growth in size or extent
shaft
an opening of uniform cross section joining a tunnel to the surface; used for access and ventilation
latitude (geographic)
angular distance from the earths center measured northerly or southerly from the equatorial plane
longitude
angular distance measured in the plane of the equator from the reference meridian through Greenwich, England. lines of longitude are indicated on globes as meridians
toe of slope
bottom of slope
layout survey
construction survey
COR
continuously operating receiver (GPS), its transmitted data can be used by single-receiver surveyors or navigators to permit higher precision differential positioning
differential leveling
determining the differences in elevation between points using a surveyors level
bearing
direction of a line given by the acute angle from a meridian and accompanied by a cardinal compass direction
gunters chain
early measuring device consisting of 100 links, measuring 66 ft long
EDM
electronic distance measurement
EFB
electronic field book (data collector)
GDOP
geometric dillution of precision: indicates the strength of figure of the satellite array as positioning signals are received
grad
gon
Hi
heigh of the line of sight of an instrument above a datum; used in leveling
hi
height of instrument (optical axis) above the instrument station; used in stadia, EDM, and GPS
laser alignment
horizontal and or vertical alignment given by a fixed or rotating laser
batter boards
horizontal cross pieces on grade stakes or grade rods that refer to proposed elevations
cut
in construction, the excavation of material; also the measurement down from a grade mark
haul
in highway construction, the distance that 1 cubic yard of cut material is transported to a fill location
turning point
in leveling, a solid point where an elevation is temporarily established so that the level may be relocated
fill
material used to raise the construction level; also the measurement up from a grade mark
universal time
mean solar time at the meridian of Greenwich, kept by atomic clocks
grid meridian
meridians paralllel to a central meridian on a coordinate grid
slope stakes
stakes placed to locate the top or bottom of a slope
hydrographic surveys
surveys designed to define shoreline and underwater features
superelevation
the banking of a curved section of road to help overcome the effects of centrifigal force
departure
the change in easterly displacement of a line (X)
precision
the degree of refinement with which a measurement is made
remote object elevation
the determination of the height of an object by a total station sighting
sag
the error caused when a tape is supported only at the ends
sea-level correction factor
the factor used to convert ground distances to sea-level equivalent distances
scale factor
the factor used to convert sea-level distances to plane grid distances
line and grade
the horizontal and vertical position of a facility
springline
the horizontal bisector of a pipe
invert
the inside bottom of a pipe or culvert
right of way
the legal limits of a utility or access route
linear error of closure
the line of traverse misclosure representing the resultant of the measuring errors
rectangular coordiatnes
the location fo a feature by two distances, 90 degrees opposed
adverse possession
the open and exclusive occupation and use of someone else's real property without permission of the owner continuously for a period of years prescribed by law, thereafter giving title o the occupier-user
waving the rod
the slight waving of the leveling rod to and from the instrument which permits the surveyor to take a precise (lowest) rod reading
resection
the solution of the coordiatnes of an occupied station by the sighting angles of three or more cooridated reference stations; two or more stations if both angels and distances are measured
common law
the system of law originating in england, as distinct from the civil or roman law and the canon or ecclesiastical law
sidereal day
the time taken for one complete revolution of the earth with reference to an infinitely faraway object eg a star
compound curve
two or more circular arcs turning in the same direction that have common tangent points and different radii
UTM
universal transervse mercator grid system
fiducial marks
reference marks on the edges of aerial photos, used to locate the principal point on the photo
differential GPS
GPS surveys in which one receiver occupies a position of know position while other receivers occupy points whose positions are to be determined
as-built (final) surveys
post-construction surveys that confirm design executions and record in-progress revisions
engineering surveys
preliminary and layout surveys used for design and construction
route survey
preliminary, control and construction surveys that cover a long but narrow area, as in highway and railroad construction
construction survey
provision of line and grade
mistake
a poor result due to carelessness or a misunderstanding
geodetic datum
a precisely established and maintained series of benchmarks referenced to adjusted Mean Seal Level (MSL)
cross section
a profile of the ground and surroundings taken at right angles to a reference line
mean sea level (MSL)
a reference datum for leveling
central meridian
a reference meridian in the center of the zone covered by the plane coordinate grid- at every 6 degrees of longitude in the UTM grid
local road (highway)
a road designed for property access, connected to arterials by collectors
arterial road (highway)
a road designed primarily for traffic mobility, with some property access consideration
collector road (highway)
a road designed to provide property access with some traffic mobility; it connects local roads to arterials
NAVSTAR
a set of orbiting satellites used in navigation and positioning
parabolic curve
a curve used in vertical alignment to join two adjacent grade lines
grid factor
a factor used to convert ground distances to grid distances
benchmark
a fixed solid reference point with a precisely determined published elevation
mass diagram
a graphic representation of cumulative highway cuts and fills
global positioning system (GPS)
a ground positioning (y,x, and z) technique based on the reception and analysis of NAVSTAR satellite signals
freeway
a highway designed for traffic mobility in which access is restricted to interchanges with arterials and other freeways
baseline
a line of reference for survey work; often the center line, street line, or the center line of construction is used, although any line could be arbitrarily selected or established
contour
a line on a map joining points of similar elevation
geographic meridian
a line on the surface of the earth joining the poles i.e a line of longitude
planimeter
a mechanical or electronic device used to measure areas by tracing the outline of the area on the map or plan
meridian
a north-south reference line
monument
a permanent reference point for horizontal and vertical positioning
plat
a plan of survey usually showing property information